In the game of golf it is typical for a player to mark the position of his golf ball on the green so that he may pick it up and clean it and also remove it from the path of other golfers. There are a variety of types, sizes and designs of both markers and holders for those markers. Many players simply use a coin or similar object carried in a pocket so they can retrieve it to mark the location of the ball.
Various devices such as clips that attach to belts, visors or other apparel also provide a location for holding the ball marker so that they can be easily utilized and then replaced.